Syringe Assembly with Inverse Delivery

ABSTRACT

A reduced profile syringe assembly is provided that includes an overall profile that is substantially similar to a profile of a syringe barrel. The syringe assembly includes a plunger rod that is significantly disposed within the syringe barrel when filled for use, with the plunger rod adapted to be retracted from the syringe barrel during dispensing of contents of the syringe barrel.

CROSS REFERENCE TO RELATED APPLICATION

This application is a continuation application of U.S. patentapplication Ser. No. 15/140,886 entitled “Syringe Assembly with InverseDelivery”, filed Apr. 28, 2016, which is a continuation application ofU.S. patent application Ser. No. 12/859,569 entitled “Syringe Assemblywith Inverse Delivery”, filed Aug. 19, 2010 (now U.S. Pat. No.9,352,096), which claims priority to U.S. Provisional Application No.61/235,805 entitled “Syringe Assembly with Inverse Delivery”, filed Aug.21, 2009, the entire disclosures of each of which are herebyincorporated herein by reference.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention is directed to a syringe assembly adapted fordispensing and delivery of a fluid. More particularly, the presentinvention is directed to a syringe assembly such as a hypodermic syringehaving a reduced profile prior to use, and which is adapted fordelivering the contents thereof through a conventional movement by theuser, but involving an inverse delivery operation.

Related Technology

Syringe assemblies, and in particular hypodermic syringes, are wellknown in the medical field for dispensing fluids, such as medication. Aconventional syringe typically includes a syringe barrel with an openingat one end and a plunger mechanism disposed through the other end. Theplunger typically includes a plunger rod extending through the barrel,with a plunger head or stopper at the end of the plunger rod within thebarrel, and with a finger flange at the other end of the plunger rodextending out of the barrel. In use, the plunger rod is retractedthrough the syringe barrel to aspirate or fill the syringe barrel with afluid, such as a medication, with the plunger rod extending out from therear end of the syringe barrel. For delivery of the medication to apatient, the opening of the syringe barrel is adapted for fluidcommunication with a patient, such as through a hypodermic needle fittedat the front end of the syringe barrel or through a luer-type fittingextending from the front end of the syringe barrel for attachment with afluid line of a patient. Upon depressing of the plunger rod, the plungerrod and stopper travel through the syringe barrel, thereby forcing thecontents of the syringe out through the opening at the front end fordelivery to the patient. Such an operation is well known in the medicalfield, and medical practitioners have become well accustomed to the useof such common fluid delivery procedures through standard syringes.

Conventional syringes are well known to be used in connection with avial of a medication, where the user draws the fluid into the syringeimmediately prior to injection and delivery of the fluid to the patient.Oftentimes, hypodermic syringes may be packaged as “pre-filled” devices,wherein the syringe is pre-filled with medication prior to beingpackaged and delivered to the end user. In this manner, there is no needfor the user to fill the device prior to injection, thereby saving timefor the end user and maintaining consistent volumes for delivery.

Packaging of such pre-filled syringes, however, tends to be bulky. Apre-filled syringe is typically packaged with the opening at the frontend of the barrel including a cap thereover and with the plunger rodretracted out of the back end of the syringe barrel, with the fluidpre-filled within the syringe barrel. Such packaging creates anelongated package that can be awkward for shipping and storage.

Pre-filled syringes are often filled with narcotics or other drugs at aproduction facility, packaged, and then shipped to a medical facility.Once at the facility, these syringes are often placed in controlledstorage and/or locked cabinets to reduce theft of the syringesthemselves and/or of the contents of these syringes. The space withinthese controlled storage locations is often limited, thus there is aneed for a syringe assembly that has a smaller packing footprint, toreduce the storage space required for containing the syringe. It is alsodesirable to produce syringes that are uniform in terms of an outersurface shape to allow for stacking of these syringes within the storagecabinet.

SUMMARY OF THE INVENTION

The present invention provides a syringe assembly having a reducedprofile prior to use, thereby occupying less space than a conventionalsyringe and providing a mechanism for reduced overall size and forefficient packaging that reduces or eliminates excess waste. Further,actuation of a syringe assembly of the present invention is accomplishedusing a similar operation as with a conventional syringe, therebyproviding a standardized mechanism for ease of use.

In one embodiment of the present invention, the reduced profile isachieved by providing a syringe assembly that, when filled, comprises anoverall profile that is substantially similar to the profile of thesyringe barrel. This may be accomplished by providing the syringeassembly with a plunger rod that is significantly disposed within thesyringe barrel when filled for use, with the plunger rod adapted to beretracted from the syringe barrel during dispensing of the contents ofthe syringe barrel.

One embodiment contemplates a syringe assembly including a syringebarrel having an inside surface defining a chamber, an open proximal orrearward end, and a distal or forward end having an openingtherethrough. A plunger assembly is disposed at least partially withinthe syringe barrel, with the plunger assembly comprising an elongatedplunger rod and a plunger head disposed on the plunger rod and slidablydisposed within the syringe barrel. The plunger head separates thechamber of the syringe barrel into a proximal chamber adjacent theproximal end and a distal chamber adjacent the distal end. A conduitextends between the proximal chamber and the opening at the distal endof the syringe barrel. The syringe assembly is adapted to contain afluid in the proximal chamber, such fluid being expelled through theconduit and out of the opening at the distal end of the syringe barrelupon movement of the plunger head toward the proximal end of the syringebarrel. Movement of the plunger head toward the proximal end of thesyringe barrel occurs based on conventional operation of expelling fluidfrom a conventional syringe with a squeezing movement between a thumband forefinger. Such movement is well recognized to syringe users, whichtypically involves squeezing between a thumb pad on a plunger rod and aforefinger on a finger flange on a syringe barrel. Through embodimentsof the present invention, an inverse delivery is accomplished withsimilar operational movement of a conventional syringe, therebyachieving a reduced profile syringe without any perceived change inoperational use by the user.

In certain embodiments, the plunger assembly may further include anactuator portion at least partially extending externally outside of thesyringe barrel and adapted to effect movement of the plunger head withinthe syringe barrel. The actuator portion may be interconnected to theplunger head, for example, through the sidewall of the syringe barrel orthrough an open proximal end of the syringe barrel. The actuator portionmay include at least one flange configured to receive a forefinger of auser, while the proximal end of the syringe barrel may be closed with aclosure that may include a thumb pad. Such flange and thumb pad areadapted to accommodate the conventional squeezing operational movementof a conventional syringe while accomplishing the inverse delivery ofthe contents of the syringe.

In another embodiment, a syringe assembly is provided including asyringe barrel having an inside surface defining a chamber, a proximalend, and a distal end having an opening therethrough. A plunger assemblyincluding a plunger head is slidably disposed within the syringe barrel,with the plunger head separating the chamber of the syringe barrel intoa proximal chamber adjacent the proximal end and a distal chamberadjacent the distal end. The syringe assembly further includes a thumbpad portion adjacent the proximal end of the syringe barrel foraccommodating a thumb of a user, and at least one finger flangeextending externally of the syringe barrel for accommodating at leastone forefinger of a user, with the finger flange adapted to effectmovement of the plunger head within the syringe barrel. Squeezingmovement between a user's thumb on the thumb pad portion and a user'sforefinger on the finger flange effects movement of the plunger headtoward the proximal end of the syringe barrel. In this manner, inversedelivery of the syringe contents is accomplished with similaroperational movement of a conventional syringe, thereby achieving areduced profile syringe without any perceived change in operational useby the user.

In yet a further embodiment, a pre-filled syringe assembly is providedincluding a syringe barrel having an inside surface defining a chamber,a proximal end, and a distal end having an opening therethrough. Theassembly further includes a plunger assembly comprising an elongateplunger rod substantially disposed within the syringe barrel and aplunger head disposed on the plunger rod and slidably disposed withinthe syringe barrel. The plunger head separates the chamber of thesyringe barrel into a proximal chamber adjacent the proximal end and adistal chamber adjacent the distal end. A conduit extends across theplunger head between the proximal chamber and the opening at the distalend of the syringe barrel. A fluid is contained in the proximal chamber,thereby providing a pre-filled syringe assembly prepared for use fordelivery of the fluid.

In still a further embodiment, a method of delivering a fluid involvesproviding: a syringe assembly comprising a syringe barrel having aninside surface defining a chamber, a proximal end, and a distal endhaving an opening therethrough; a plunger assembly comprising anelongate plunger rod and a plunger head disposed on the plunger rod andslidably disposed within the syringe barrel, the plunger head separatingthe chamber of the syringe barrel into a proximal chamber adjacent theproximal end and a distal chamber adjacent the distal end, wherein afluid is contained in the proximal chamber; and a conduit extending theplunger assembly further comprising an actuator portion which at leastpartially extends externally outside of the syringe barrel between theproximal chamber and the opening at the distal end of the syringebarrel. The method further involves positioning a thumb on the syringeassembly at a position proximate to the proximal end of the syringebarrel, and at least one forefinger on the actuator portion, andapplying a squeezing motion to move the at least one forefinger and thethumb toward each other. Such motion moves the actuator portion towardthe proximal end of the syringe barrel and effects movement of theplunger head toward the proximal end of the syringe barrel to expelfluid contained in the proximal chamber through the conduit and out ofthe syringe barrel through the opening in the distal end.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a perspective view of a syringe assembly in one embodiment ofthe present invention shown in a pre-filled state prior to use.

FIG. 1B is a front plan view of the syringe assembly of FIG. 1A.

FIG. 1C is a side plan view of the syringe assembly of FIG. 1A.

FIG. 1D is a side cross-sectional view of the syringe assembly of FIG.1A.

FIG. 2 is a perspective view of the syringe assembly of FIG. 1A shownduring use by a user.

FIG. 3 is a perspective view of the syringe assembly of FIG. 1A shownafter use by a user after the medication is expelled.

FIG. 4A is a perspective view of the syringe assembly of FIG. 1A shownafter dispensing of the medication after use.

FIG. 4B is a front plan view of the syringe assembly of FIG. 4A afteruse.

FIG. 4C is a side plan view of the syringe assembly of FIG. 4A afteruse.

FIG. 4D is a side cross-sectional view of the syringe assembly of FIG.4A after use.

FIG. 5A is a side plan view of a syringe assembly similar to that ofFIG. 1A shown in a pre-filled state prior to use and further including abellows.

FIG. 5B is a side cross-sectional view of the syringe assembly of FIG.5A.

FIG. 5C is an enlarged side cross-sectional view of FIG. 5A showing thedetails of the bellows.

FIG. 6A is a side plan view of the syringe assembly of FIG. 5A shownafter dispensing the medication after use with the bellows expanded.

FIG. 6B is a side cross-sectional view of the syringe assembly of FIG.6A.

FIG. 6C is an enlarged side cross-sectional view of FIG. 6A showing thedetails of the expanded bellows.

FIG. 7A is a perspective view of a syringe assembly in a furtherembodiment shown in a pre-filled state prior to use.

FIG. 7B is a front plan view of the syringe assembly of FIG. 7A.

FIG. 7C is a side plan view of the syringe assembly of FIG. 7A.

FIG. 7D is a side cross-sectional view of the syringe assembly of FIG.7A.

FIG. 8A is a perspective view of the syringe assembly of FIG. 7A shownafter dispensing of the medication after use.

FIG. 8B is a front plan view of the syringe assembly of FIG. 8A afteruse.

FIG. 8C is a side plan view of the syringe assembly of FIG. 8A afteruse.

FIG. 8D is a side cross-sectional view of the syringe assembly of FIG.8A after use.

FIG. 9 is a side cross-sectional view of a syringe assembly in a furtherembodiment shown in a pre-filled state prior to use.

FIG. 10 is a side cross-sectional view of the syringe assembly of FIG. 9shown after dispensing of the medication after use.

FIG. 11 is a side cross-sectional view of a syringe assembly in yet afurther embodiment shown in a pre-filled state prior to use.

FIG. 12 is a side cross-sectional view of the syringe assembly of FIG.11 shown after dispensing of the medication after use.

FIG. 13 is a perspective view comparing a conventional syringe to asyringe assembly in accordance with the present invention.

DETAILED DESCRIPTION

For purposes of the description hereinafter, the terms “upper”, “lower”,“right”, “left”, “vertical”, “horizontal”, “top”, “bottom”, “lateral”,“longitudinal”, and derivatives thereof shall relate to the invention asit is oriented in the drawing figures. However, it is to be understoodthat the invention may assume various alternative variations, exceptwhere expressly specified to the contrary. It is also to be understoodthat the specific devices illustrated in the attached drawings, anddescribed in the following specification, are simply exemplaryembodiments of the invention. Hence, specific dimensions and otherphysical characteristics related to the embodiments disclosed herein arenot to be considered as limiting.

Reference is now made to FIGS. 1A-1D, which depict a syringe assembly,generally indicated as 10, adapted for dispensing and delivery of afluid. Syringe assembly 10 is intended for use for injection or infusionof fluid such as a medication into a patient, and is generally shown anddescribed for purposes of the present description as a hypodermicsyringe. Syringe assembly 10 is contemplated for use in connection witha needle such as by connecting syringe assembly 10 to a separate needleassembly (not shown), or alternatively for connection with anintravenous (IV) connection assembly.

Syringe assembly 10 includes syringe barrel 12 defined by barrel wall 14extending between a forward or distal end 16 and a rearward or proximalend 18, thereby defining interior chamber 20 of syringe barrel 12.Syringe barrel 12 may be in the general form of an elongated cylindricalbarrel as is known in the art for the general shape of a hypodermicsyringe, although other forms for containing a fluid for delivery arealso contemplated. Forward end 16 of syringe barrel 12 includes anoutlet opening 22, and rearward end 18 is generally open-ended, but isintended to be closed off to the external environment, as will bediscussed in more detail herein. Syringe barrel 12 may include markings,such as graduations 26 on the wall thereof, for providing an indicationas to the level or amount of fluid contained within syringe barrel 12.Such markings may be provided on the external wall, the internal wall,or integrally formed or otherwise within the wall of syringe barrel 12.Alternatively or in addition thereto, the markings may provide adescription of the contents of the syringe, or other identifyinginformation, as may be known in the art.

As noted, forward end 16 of syringe barrel 12 includes an outlet opening22. The profile of outlet opening 22 may be adapted for engagement witha separate device, such as a needle assembly or IV connection assembly,and therefore may include a mechanism for such engagement, for example,a generally tapered luer tip 28, for engagement with a separate taperedluer mating surface (not shown) of such a separate device for attachmenttherewith. In addition, a mechanism for locking engagement therebetweenmay also be provided, such as luer lock 30 including interior threads32. Such luer connections and luer locking mechanisms are well known inthe art. Additionally, syringe barrel 12 includes at least one openingthrough the wall thereof extending into the interior chamber 20 adjacentforward end 16, such as vent 34, the use of which will be described infurther detail herein.

Syringe assembly 10 further includes a plunger assembly 40, a portion ofwhich is disposed at least partially within syringe barrel 12. Plungerassembly 40 provides a mechanism for dispensing fluid contained withinthe interior chamber 20 of syringe barrel 12. In particular, plungerassembly 40 includes a plunger head or stopper portion 50 disposedwithin interior chamber 20, and in contact with the internal surface ofsyringe barrel wall 14, thereby separating interior chamber 20 into aproximal chamber 20 a adjacent proximal or rearward end 18, and a distalchamber 20 b adjacent distal or forward end 16 of syringe barrel 12.Plunger head 50 may include one or more annular ribs extending about theoutside perimeter thereof, such as rib 52, for providing sealingengagement with the interior surface of syringe barrel wall 14.

Plunger head 50 is adapted for movement within the interior chamber 20of syringe barrel 12, with plunger head 50 sliding or riding along theinterior surface of syringe barrel wall 14. Such movement may beeffected by a separate actuator portion of plunger assembly 40 which atleast partially extends externally outside of syringe barrel 12. Forexample, an actuator in the form of a perimetrical flange collar 48including finger flanges 48 a and 48 b may extend external to syringebarrel 12, for example, along the external surface of syringe barrelwall 14, and may be interconnected with plunger head 50, such asdirectly through an opening or channel through wall 14, through anassembly which extends through generally open-ended rearward end 18 ofsyringe barrel 12, or through a further interconnection. While theactuator is shown as a flange collar 48 including a pair of fingerflanges 48 a, 48 b, it is contemplated that any number of finger flangesmay be present.

In one embodiment as depicted in FIGS. 1A-1D, plunger assembly 40includes a plunger rod 42 for connecting plunger head 50 with externalflange collar 48 and finger flanges 48 a and 48 b. Plunger rod 42 andplunger head 50 may be integrally formed, or may be separate elementsthat are attached or otherwise interconnected together. For example,plunger rod 42 may be constructed of a stiff polymeric material, withplunger head 50 formed from a separate silicone or rubberized materialthat is molded integrally with plunger rod 42, such as through atwo-shot molding process, or may be a separate material that ismechanically attached or adhesively fixed to plunger rod 42.

Various assemblies are contemplated for interconnecting actuator portionof plunger assembly 40 with plunger head 50 through open rearward end 18of syringe barrel 12. For example, plunger rod 42 of plunger assembly 40may include a first elongated portion that is connected with plungerhead 50 and that extends within the interior 20 of syringe barrel 12 andout through open rearward end 18 of syringe barrel 12. As shown in FIG.1D, plunger assembly 40 may further include an external arm 44 extendingexternally along syringe barrel 12 for connection with flange collar 48and finger flanges 48 a and 48 b, and with connecting arm 46interconnecting internal plunger rod 42 and external arm 44. In thismanner, finger flanges 48 a, 48 b are interconnected with plunger head50 through the open rearward end 18 of syringe barrel 12 by way ofexternal arm 44, connecting arm 46, and internal plunger rod 42,respectively.

As noted, rearward end 18 of syringe barrel 12 is open-ended. Syringeassembly 10 may further be provided with a closure, such as cap 60, forclosing the open rearward end 18 of syringe barrel 12, thereby providinginterior chamber 20 as a closed chamber. Cap 60 includes an elongatedportion in the form of neck 62 that has an outer diameter substantiallythe same as an inner diameter of syringe wall 14, so as to provide aninterference fit therein, thereby holding cap 60 in place. Cap 60 may befixedly adhered in place, such as through a mechanical engagement, abiocompatible adhesive, sonic welding, etc. Cap 60 includes a finger padportion 64 that extends external to syringe barrel 12, which may beprovided with finger ribs 66 for providing a tactile surface for a user.Cap 60 may also include an angled profile 68 on the end of neck 62extending within syringe barrel 12, providing a recessed area adjacentproximal end 18 of syringe barrel 12 for accommodating the outflow offluid, as will be described in more detail herein. Plunger head 50 mayalso include an angled profile 54 at a proximal end thereof forcooperating engagement with angled profile 68 of cap 60 upon fulldisplacement of plunger head 50 within interior chamber 20, as will bedescribed in further detail.

Syringe assembly 10 further includes a conduit 70 extending between afirst end 72 positioned adjacent forward end 16 of syringe barrel 12,and a second end 74 positioned adjacent rearward end 18 of syringebarrel 12, with fluid channel 76 extending therethrough. Conduit 70extends across plunger head 50, with first end 72 of conduit 70extending within or through forward opening 22 of syringe barrel 12,providing for fluid communication with forward opening 22, and withsecond end 74 of conduit 70 extending within proximal chamber 20 a, suchthat fluid channel 76 is in fluid communication with proximal chamber 20a. Second end 74 of conduit 70 may be positioned within the recess atproximal end 18 created by the angled profile 68 of cap 60. In thismanner, the rearward-most or proximal-most portion of proximal chamber20 a is established by the recess of angled profile 68, with an inletinto conduit 70 provided at second end 74 being positioned in thisproximal-most portion of proximal chamber 20 a. This positioning isparticularly useful for removing any air trapped within proximal chamber20 a prior to expelling any drug therefrom, as will be described in moredetail with respect to the use of syringe assembly 10.

All of the components of syringe assembly 10 may be constructed of anyknown material, and are desirably constructed of medical grade polymers.

Syringe assembly 10 is particularly useful as a pre-filled syringe, andtherefore may be provided for end use with a fluid, such as amedication, contained within proximal chamber 20 a of syringe barrel 12,pre-filled by the manufacturer. In this manner, syringe assembly 10 canbe manufactured, pre-filled with a medication, sterilized, and packagedin appropriate packaging for delivery, storage, and use by the end user,without the need for the end user to fill the syringe with medicationfrom a separate vial prior to use.

In use, syringe assembly 10 is provided with a medication pre-filled andcontained within proximal chamber 20 a of syringe barrel 12. For use,syringe assembly 10 is grasped with the user's thumb on finger pad 64and with the user's fingers extending between finger flanges 48 a and 48b of flange collar 48. In this manner, syringe assembly 10 is grasped bythe user in a well known and well recognized manner similar to theoperation of a conventional hypodermic syringe.

Prior to dispensing of medication, any air trapped within proximalchamber 20 a can be expelled by arranging syringe assembly 10 with theforward end 16 pointed downward, such that any air within proximalchamber 20 a will be forced toward rearward end 18 at the recessed areaestablished by the angled profile 68 of cap 60. With second end 74 ofconduit 70 positioned within this recess adjacent angled profile 68,initial movement of plunger assembly 40, by sliding movement of plungerhead 50, will cause any such air trapped within proximal chamber 20 a atthe recess of angled profile 68 to be expelled through second end 74,into conduit 70 and out first end 72 into outlet opening 22 out fromsyringe barrel 12 prior to any medication being expelled.

The user can attach luer tip 28 to a separate needle assembly or IVconnection assembly and lockingly engage through threads 32 of luer lock30 in a known manner. When it is desired to deliver the medication, theuser effects a squeezing movement between the thumb and forefingers asshown in FIG. 2, thereby causing finger flanges 48 a, 48 b and flangecollar 48 to move in the direction of arrow A away from distal orforward end 16 and toward proximal or rearward end 18. Such movement offinger flanges 48 a, 48 b and flange collar 48 is transferred to plungerhead 50 through the interconnection of internal plunger rod 42, externalarm 44, and connecting arm 46 that interconnects plunger head 50 withflange collar 48. Such movement of plunger head 50 within interiorchamber 20 of syringe barrel 12 reduces the volume of proximal chamber20 a, thereby creating a positive pressure therein. In order to preventa negative pressure within distal chamber 20 b, air can be drawn intodistal chamber 20 b through vent 34, which provides a mechanism for airflow between distal chamber 20 b and the external environment.

Since proximal chamber 20 a is sealed to the external environmentthrough plunger head 50 and through cap 60 at a rearward opening 24, themedication fluid within proximal chamber 20 a is forced into fluidchannel 76 at second end 74 of fluid conduit 70. Such fluid medicationtravels through fluid channel 76 and out through first end 72 of conduit70, entering into forward opening 22. In this manner, the fluidmedication can be expelled from the syringe barrel 12 through forwardopening 22, and into the separate needle assembly or IV assembly andinto the patient.

Upon full movement of plunger head 50 through syringe barrel 12, plungerhead 50 “bottoms out”, with plunger head 50 contacting the internal endof cap 60, as shown in FIGS. 3 and 4A-4D, with the corresponding angledprofiles 54, 68 of plunger head 50 and cap 60, respectively, incorresponding engagement. The second end of conduit 74 is arrangedwithin proximal chamber 20 a at a position adjacent the portion of theangled profile 68 of cap 60 that is closest to proximal or rearward end18. In this manner, the fluid medication is funneled toward first end 72of conduit 70, and the internal volume of proximal chamber 20 a remainsfilled with fluid medication through the entire sliding movement ofplunger head 50 through syringe barrel 12. At this point, plunger rod42, external arm 44, and connecting arm 46 all extend substantiallyexternally of syringe barrel 12.

With such an arrangement, the overall size and shape of syringe assembly10 when filled for use is of an overall profile similar to aconventional syringe after use, with a plunger completely extendedwithin a syringe barrel, as seen in FIG. 13, which depicts the profileof a conventional syringe 1 in comparison to syringe assembly 10 inaccordance with an embodiment of the present invention. As such, theprofile is significantly reduced from that of a conventional pre-filledsyringe, which includes the plunger retracted from the barrel prior touse.

FIGS. 5A-5C and 6A-6C depict syringe assembly 10 in an alternateembodiment that is substantially the same as that described above withrespect to FIGS. 1A-4D, but further including a mechanism for preventingexposure to the syringe contents and for preventing contamination. Inparticular, during the injection and syringe discharge sequence asdescribed above, the plunger rod 42 is retracted from within the syringebarrel 12. Prior to such retraction, the plunger rod 42 is in directcontact with the fluid contained within the proximal chamber 20 a ofsyringe barrel 12. In order to prevent the user from being exposed tothe contents of the syringe during the retraction of the plunger rod 42based on the plunger rod 42 being “wetted” with such fluid, a barrier,such as an expandable bellows 80, can be provided. Bellows 80 canencompass the portion of plunger rod 42 that extends external to syringebarrel 12 during retraction. As such, bellows 80 encompasses and wrapsaround the externally exposed portion of plunger rod 42, and is adaptedto expand upon retraction of plunger rod 42. For example, bellows 80 maybe of an accordion-style construction, interconnected between an end ofplunger rod 42 adjacent connecting arm 46 and extending to cap 60 at alocation where plunger rod 42 extends through cap 60. When syringeassembly 10 is in a pre-filled state prior to use with plunger rod 42extending within syringe barrel 12, bellows 80 is at least partially,and likely fully, collapsed, as shown in FIGS. 5A-5C. When plunger rod42 is retracted to the exterior upon movement of finger flanges 48 a, 48b, bellows 80 expands to encompass and maintain plunger rod 42 in asealed environment. As such, any fluid in contact with plunger rod 42 ismaintained within bellows 80 and is prevented from contacting the user.Moreover, if the user pushes the plunger rod 42 back into syringe barrel12 during or after use, sterility is maintained within the syringebarrel 12, since bellows 80 prevents plunger rod 42 from contacting theexternal environment.

FIGS. 7A-7D and 8A-8D depict a syringe assembly in a further embodimentsimilar to that described above in the embodiments of FIGS. 1A-4C, butwith a different arrangement for the conduit. In particular, in theembodiment of FIGS. 7A-7D and 8A-8D, conduit 170 is provided as anexpandable or extendable member adapted for movement with plunger head50. Conduit 170 is similar to conduit 70 described above, including aninternal fluid channel extending between a first end 172 and a secondend 174, and across plunger head 50, with first end 172 positionedadjacent forward end 16 of syringe barrel 12. In this embodiment,however, the second end 174 of conduit 170 extends across plunger head50 and into proximal chamber 20 a at a position directly adjacent therearward or proximal end of plunger head 50, with second end 174 fixedwith plunger head 50. As such, the fluid channel extending throughconduit 170 is in fluid communication with proximal chamber 20 adirectly at the area of contact between plunger head 50 and proximalchamber 20 a when syringe assembly 10 is in a pre-filled state prior touse, as opposed to extending entirely through syringe barrel 12 torearward end 18 prior to use as in the prior embodiments. Furthermore,in the embodiment of FIGS. 7A-7D and 8A-8D, conduit 170 is extendable,such that when plunger head 50 slides or moves along syringe wall 14within syringe barrel 12, the second end 174 of conduit 170 moves withplunger head 50. This may be accomplished, for example, by providingconduit 170 as a flexible tubing that can be contained within distalchamber 20 b prior to use of syringe assembly 10 and extended duringuse, or as a wound coil that can be extended during use, or othermanner.

Operation of syringe assembly 10 depicted in the embodiment of FIGS.7A-7D and 8A-8D is similar to that of the prior described embodiments.It is noted, however, that in the embodiment of FIGS. 7A-7D and 8A-8D,syringe assembly 10 does not have to be arranged with the forward end 16pointed downward in order to first expel any trapped air from within thesyringe, but instead can be arranged with the forward end 16 pointedupward, as in a more conventional syringe operation, since the initialpoint of fluid flow out of proximal chamber 20 a occurs directly at theinterface of plunger head 50 within proximal chamber 20 a in thisembodiment. To expel medication, plunger assembly 40 is actuated as inthe prior embodiment, upon movement of flange collar 48 through fingerflanges 48 a, 48 b to cause movement of plunger assembly 40, thuscausing fluid to flow from within proximal chamber 20 a into the fluidchannel of conduit 170 directly at second end 174 and out first end 172.

FIGS. 9 and 10 depict yet a further embodiment of a syringe assembly inaccordance with the present invention. Syringe assembly 10 of FIGS. 9-10includes similar components as that of the previously describedembodiments of FIGS. 1A-4D, but with conduit 70 extending radiallycentered with respect to the general elongated axis of syringe assembly10.

In a further embodiment, it is contemplated that a controlled dosingsystem could be provided. For example, an external surface of thesyringe barrel 12 may be provided with notches or protrusions along thegraduations of the syringe barrel 12 at predetermined increments, suchas at each 1 ml increment. A further protrusion or flap would also beprovided on the flange collar 48, such as a flap extending around atleast a portion of the internal perimeter of flange collar 48. As flangecollar 48 rides along the outer surface of syringe barrel 12 toward therearward end 18 during delivery of the medication, the flap on theflange collar 48 would contact and interfere with each successive notchor protrusion on the syringe barrel 12, thereby providing an audible ortactile indication to the user of each predetermined dosage increment.In this manner, the user could hear or feel when each volume of dosageis delivered in specific increments.

FIGS. 11 and 12 depict an alternate embodiment of a syringe assembly inaccordance with the present invention. This alternate embodimentdepicted in FIGS. 11 and 12 repositions the outlet end of the syringeassembly at the retraction end of the plunger rod. More particularly,syringe assembly 200 includes a syringe barrel 212 having a wall 214extending between first end 216 and second end 218, forming an interiorchamber 220 therein. First end 216 includes an opening 222, including aluer tip 228, which may be offset from the central axis of syringeassembly 200. Vent 238 is positioned adjacent second end 218.

Syringe assembly 200 further includes plunger assembly 240 includingplunger rod 242 connected with plunger head 250. Plunger head 250separates interior 220 of syringe barrel 212 into two distinct chambers,namely, first chamber 220 a and second chamber 220 b. Plunger rod 242extends within interior 220 of syringe barrel 212 and out to theexternal environment through first end 216.

With such an arrangement, syringe assembly 200 works as follows. Fluidsuch as medication is contained within first chamber 220 a of syringebarrel 212. To expel the medication, plunger assembly 240 is activatedby pulling on plunger rod 242, thereby causing plunger head 250 to slidewithin syringe barrel 212. Medication is forced out through opening 222at first end 216 of syringe barrel 212, which is in fluid communicationwith first chamber 220 a. Vent 238 prevents negative pressure withinsecond chamber 220 b. In this manner, medication can be expelled anddelivered through luer tip 228. Such an embodiment is similar to theprior discussed embodiments, albeit with the syringe opening 222arranged in an opposite end of the assembly.

In each of the embodiments provided herein, the overall profile anddimensions of a syringe assembly when filled with a fluid such asmedication prior to use is significantly reduced when compared with atraditional syringe. This reduced profile is accomplished by maintaininga significant portion of the plunger rod that is used for extending thestopper or plunger head within the syringe barrel when the syringeassembly is filled for use. Thus, the plunger rod occupies little spaceprior to use, thereby reducing packaging and eliminating waste. Fordisposal, the clinician has the option to push the plunger rod to itsstarting position to reduce the overall profile for disposal, such as ina sharps disposal container, thereby reducing the amount of storagespace required for disposal.

In addition, certain embodiments involve a conventional operation foruse of the syringe assembly to expel medication. For example, thetactile surfaces of the syringe assembly of the present inventioninclude finger flanges and thumb presses situated for accommodating auser's fingers and thumb in a similar manner as with conventionalsyringes, such that a conventional squeezing movement expels themedication, albeit with a different arrangement within the syringeassembly causing an inverse movement of the fluids therein. As such, theuser perceives no change in operation or use to dispense the medicationeven with the decreased overall profile of the assembly.

What is claimed is:
 1. A syringe assembly having a reduced profile priorto use, comprising: a syringe barrel having an inside surface defining achamber, an open proximal end, and a distal end having an openingtherethrough; a plunger assembly disposed at least partially within thesyringe barrel, the plunger assembly comprising an elongate plunger rodand a plunger head disposed on the plunger rod and slidably disposedwithin the syringe barrel, the plunger head separating the chamber ofthe syringe barrel into a proximal chamber adjacent the proximal end anda distal chamber adjacent the distal end; and a conduit extending acrossthe plunger head between the proximal chamber and the opening at thedistal end of the syringe barrel, wherein the conduit is radiallycentered with respect to a general elongated axis of the syringe barrel,wherein the syringe assembly is adapted to contain a fluid in theproximal chamber, wherein the fluid contained within the proximalchamber is adapted to be expelled through the conduit and out of theopening at the distal end of the syringe barrel upon movement of theplunger head toward the proximal end of the syringe barrel, and whereinmovement of the plunger head toward the proximal end of the syringebarrel occurs based on conventional operation of expelling fluid from aconventional syringe with a squeezing movement between a thumb andforefinger.
 2. The syringe assembly of claim 1, wherein, upon movementof the plunger head toward the proximal end of the syringe barrel, theconduit remains fixed with respect to the syringe barrel.
 3. The syringeassembly of claim 1, wherein an external surface of the syringe barrelcomprises notches or protrusions at predetermined increments adapted tointeract with a corresponding flap extending from an interior perimeterof the actuator portion to provide an indication of movement of theplunger head within the syringe barrel.
 4. A syringe assembly having areduced profile prior to use, comprising: a syringe barrel having aninside surface defining a chamber, a first end, and a second end havingan opening therethrough; an opening located at the first end, theopening being offset from a central axis of the syringe assembly; a ventlocated adjacent the second end; and a plunger assembly comprising aplunger head slidably disposed within the syringe barrel and a plungerrod associated with the plunger head, the plunger head separating thechamber of the syringe barrel into a first chamber adjacent the firstend and a second chamber adjacent the second end, wherein a pullingmovement on the plunger rod causes movement of the plunger head towardthe first end of the syringe barrel causing the syringe contents to beexpelled through the opening located at the first end.
 5. The syringeassembly of claim 4, wherein the opening is associated with a luer tip.6. The syringe assembly of claim 4, wherein the vent is configured toprevent negative pressure within the second chamber.
 7. The syringeassembly of claim 4, wherein the plunger assembly includes an actuatorportion at least partially extending outside the first end of thesyringe barrel.
 8. A method of delivering a fluid, comprising: providinga syringe assembly having a reduced profile prior to use comprising: asyringe barrel having an inside surface defining a chamber, a first end,and a second end having an opening therethrough; an opening located atthe first end, the opening being offset from a central axis of thesyringe assembly; a vent located adjacent the second end; and a plungerassembly comprising a plunger head slidably disposed within the syringebarrel and a plunger rod associated with the plunger head, the plungerhead separating the chamber of the syringe barrel into a first chamberadjacent the first end and a second chamber adjacent the second end;providing an actuator portion at least partially extending outside thefirst end of the syringe barrel, said actuator portion being associatedwith the plunger rod; and applying a pulling force to the actuator tocause the plunger rod and plunger head to move within the syringe barreltoward the first end of the syringe barrel causing the syringe contentsto be expelled through the opening located at the first end.